In recent years, with the popularity of consumer electronic products and the development of the Internet, information from different regions of the world can be fast spread and shared by people globally. In addition, the interconnection architecture of the Internet nowadays also gradually changes from a wired structure based on connection of cables, optical fibers, and the like to a wirelessly-connected structure, so as to solve the problem that the circuit layout is too complicated and at the same time provide users with a convenient and humanized communication environment.
For the wirelessly-connected structure, the wireless communications technology in which the electromagnetic wave is used to transmit a signal is also widely applied to various types of electronic devices such as notebook computers, mobile phones, wearable devices, and the like. Therefore, an antenna structure for receiving and sending electromagnetic wave signals becomes an indispensable component of the electronic devices. Currently, an antenna structure may be exposed outside an electronic device or built inside an electronic device. However, the exposed antenna structure not only affects the volume and external appearance of the electronic device, but also may be easily bent or damaged by an external force. Therefore, the built-in antenna structure has become the mainstream trend.
Refer to FIG. 1, which is a schematic structural diagram of a conventional antenna structure. The antenna structure 1 shown in FIG. 1 is a planar inverted-F antenna, and includes a radiation component 11, a short-circuit pin 12, a signal feed-in component 13, and an inductor-capacitor circuit (LC circuit) 14 disposed on a circuit board 2. In addition, two ends of the short-circuit pin 12 are separately connected to the radiation component 11 and the ground end 21 that is on the circuit board 2, two ends of the signal feed-in component 13 are separately connected to the radiation component 11 and the inductor-capacitor circuit 14, and a current from a signal processing unit 22 on the circuit board 2 flows through the signal feed-in component 13, and is transmitted to the radiation component 11, so that the radiation component 11 further transmits a radiation signal to the external. To achieve impedance matching between the antenna structure 1 and the signal processing unit 22, or to enable the antenna structure 1 to meet specifications and performance needed in actual use, a current method is to change the shape of the inductor-capacitor circuit 14 or the antenna structure 1. The antenna structure 1 shown in FIG. 1 is well known by a person skilled in the art, and therefore, details are not described herein.
However, the conventional antenna structure 1 has the following defects: first, inductance and capacitance in the inductor-capacitor circuit 14 causes an energy loss; second, for different electronic devices using the antenna structure 1, the shape of the antenna structure 1 must be changed to achieve desired performance; however, if the shape of the antenna structure 1 is too complicated, the mold used for manufacturing the antenna structure 1 also becomes more complicated, thereby increasing manufacture costs and causing difficulty to large-scale production. Therefore, the conventional antenna structure 1 needs to be improved.